Handheld consumer electronic devices such as cellular telephones, portable internet devices, portable music players, and hand held gaming devices often include some form of visual display, such as a flat screen video display or a touchscreen display. Touchscreens are displays which also have the ability to detect the location of touches within the display area. This allows the display to be used as an input device, removing the keyboard and/or the mouse as the primary input device for interacting with the display's content. Such displays can be attached to computers or, as terminals, to networks. Touchscreens also have assisted in recent changes in the design of personal digital assistant (PDA), satellite navigation and mobile phone devices, making these devices more usable.
Touchscreens have become commonplace since the invention of the electronic touch interface in 1971 by Dr. Samuel C. Hurst. They have become familiar in retail settings, on point of sale systems, on automatic teller machines (ATMs) and on PDAs where a stylus is sometimes used to manipulate a graphical user interface (GUI) and to enter data. The popularity of smart phones, PDAs, portable game consoles and many types of information appliances is driving the demand for, and the acceptance of, touchscreens.
The visual displays used in hand-held devices are relatively small compared to computer screens or television screens. This often makes it difficult to see information displayed on the screen. Some hand-held devices allow the display to zoom-in on a selected portion of a larger image so that the selected portion may be magnified and viewed in greater detail. To implement such a zoom feature typically requires the hand-held device to implement some way of selecting the portion to be magnified. Prior art solutions include the use of a touchscreen as the visual display and software that allows the user to select the portion of the display to be magnified with his fingers or a stylus. Unfortunately, because the screen is small, the user's fingers often obscure the part that is to be selected making selection difficult.
It is within this context that embodiments of the present invention arise.